Cooking appliances generally have one or more heat sources for preparing food in a cooking chamber. In this case, a combination of different heat sources is often particularly expedient, as the heat sources then supplement one another with respect to their advantages. Thus, for example, a microwave heat source has very good efficiency as the energy of the microwaves is immediately available and the food is cooked from the inside. Steam heat sources, for example, allow particularly gentle cooking and prevent food from drying out during cooking.
The combination of different heat sources is a technical challenge, in particular in the case of so-called combined appliances having a microwave heat source and a thermal heat source. On the one hand, in a combined appliance of this type, the cooking chamber together with the cooking containers used must be heat-resistant in relation to the temperatures to be expected when operating the thermal heat source. On the other hand, when using microwave heat sources, care has to be taken that unfavourable heat and voltage flashovers do not occur due to the power input.
Care should be taken particularly in the design of cooking containers for combined appliances of this type to ensure that flashovers do not occur between the cooking container and cooking chamber, as such flashovers can spoil the appearance of the cooking container or even damage it and also affect the cooking chamber casing.
Cooking containers are therefore known from the prior art, which are formed of plastics material or ceramic. In addition, cooking containers made of metal are also known, the use of which, however, in microwave operation, is prohibited by the manufacturers. In commercial appliances, metallic cooking containers, which are received in tray trolleys in such a way that the spacing from the cooking chamber is very large, are known. The drawback in this is the very high space requirement, so solutions of this type are ruled out in the tight dimensions of a household appliance.